vant-weapp/dist/mixins/page-scroll.js

function getCurrentPage() {
    const pages = getCurrentPages();
    return pages[pages.length - 1] || {};
}
function onPageScroll(event) {
    const { vanPageScroller = [] } = getCurrentPage();
    vanPageScroller.forEach((scroller) => {
        if (typeof scroller === 'function') {
            scroller(event);
        }
    });
}
export const pageScrollMixin = (scroller) => Behavior({
    attached() {
        const page = getCurrentPage();
        if (Array.isArray(page.vanPageScroller)) {
            page.vanPageScroller.push(scroller.bind(this));
        }
        else {
            page.vanPageScroller = [page.onPageScroll, scroller.bind(this)];
        }
        page.onPageScroll = onPageScroll;
    },
    detached() {
        const page = getCurrentPage();
        page.vanPageScroller = (page.vanPageScroller || []).filter(item => item !== scroller);
    }
});